Stream `merge` function calls `poll_next` again after returning `Poll::Ready(None)` about futures-concurrency

[phil-opp]

Perfect, thanks a lot!

[yoshuawuyts]

Oops, that's not good. I believe you already reported this a while back, so I apologize for the regression. Let's fix this ASAP.

[yoshuawuyts]

Okay, so I'm trying to repro it on the main branch, and the following test seems to pass without any problem:

    #[test]
    fn main() {
        block_on(async {
            let create_stream = |count| {
                futures::stream::unfold(count, |n| async move {
                    if n > 1 {
                        Some((n, n - 1))
                    } else {
                        None
                    }
                })
            };
            let stream_1 = create_stream(10);
            let stream_2 = create_stream(10);

            let merged = (stream_1, stream_2).merge();
            futures::StreamExt::collect::<Vec<_>>(merged).await;
            // merged.collect::<Vec<_>>().await;
        })
    }

I tried replacing future_lite::StreamExt with futures::StreamExt, and both seem to work. What version of futures-concurrency do you have in your Cargo.lock file?

[phil-opp]

Ah, I used the latest crates.io release, v7.0.0. I just retried with the latest master commit and it looks like the issue is fixed there.

[phil-opp]

I tried to pinpoint the commit and it looks like #96 fixed the issue.

[yoshuawuyts]

Okay! -- Seems like the right thing to do is then to publish a new release. On it!

[yoshuawuyts]

Published! https://github.com/yoshuawuyts/futures-concurrency/releases/tag/v7.1.0